Title: How to use the C-reactive protein in pediatrics<br/>Author: Jenny Guyther<br/><a href='http://umem.org/profiles/faculty/314/'>[Click to email author]</a><hr/><p>
Historically, the C-reactive protein (CRP) has been used in the assessment of the febrile child and is the only biomarker recommended by the National Institute for Health and Care Excellence (NICE).</p>
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CRP increases 4-6 hours after the onset of inflammation, doubling every 8 hours and peaking at 36-50 hours. It rapidly decreases once the inflammation has resolved.</p>
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An elevated CRP alone is not conclusive of a serious bacterial infection (SBI).</p>
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A CRP >75 <strong>mg/L </strong>increased the relative risk of SBI by 5.4.</p>
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A CRP <20 <strong>mg/L</strong> decreased the risk of SBI, but there was still a small subset of children where SBI was present.</p>
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In infants < 3 months initial CRP measurements are poorly accurate, but when trended may be useful in deciding when to stop antibiotics (rather then when to start them). A normalizing CRP demonstrated a 100% negative predictive value for excluding invasive bacterial infection.</p>
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<strong>Bottom line:</strong></p>
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CRP is <strong>not </strong>a rule in/rule out test</p>
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CRP is <strong>not </strong>helpful in diagnosing SBI, but serial measurements may be useful in monitoring response to treatment</p>
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CRP has a limited role in well appearing children older than 3 months</p>
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<span style="display: inline !important; float: none; background-color: transparent; color: rgb(34, 34, 34); font-family: Calibri,sans-serif; font-size: 14.66px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; line-height: 16px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">Dyer EM, Waterfield T, Baynes H.</span><span style="background-color: transparent; color: rgb(34, 34, 34); font-family: Calibri,sans-serif; font-size: 14.66px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"> </span><span style="display: inline !important; float: none; background-color: transparent; color: rgb(34, 34, 34); font-family: Calibri,sans-serif; font-size: 14.66px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; line-height: 16px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">How to use C-reactive protein.</span><span style="background-color: transparent; color: rgb(34, 34, 34); font-family: Calibri,sans-serif; font-size: 14.66px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"> </span><span style="display: inline !important; float: none; background-color: transparent; color: rgb(34, 34, 34); font-family: Calibri,sans-serif; font-size: 14.66px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; line-height: 16px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">Arch Dis Child Educ Pract Ed 2018; 0:1-4.</span></p>
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